Error Message "no SIM card installed" How can I fix it??

If your phone displays an error message saying "sim card rejected and sim access" then your phone is probably network locked.

If your model is Blackberry visit UnBBlock.com and if your phone is an other GSM phone visit SimpleUnlocking.com here they are providing the unlock code at reasonable cost with easy step by step unlocking instructions and unlock it.

Install or replace the SIMM card.

This is a simple fix. Just pop the sim card out and put it back in. Sometimes you only need to disconnect the sim totally to refresh the cellular connectivity.

For detailed guide on pulling out the iPhone sim card, CLICK HERE.

For more iPhone tips and tricks, see THIS LIST.

You have to check if your SIM card (chip) is correctly installed, this one is provided and normally installed by your cell phone company, if you won't use cellular phone function, just deactivate it in galaxy tab setup.

• Clean the connectors on the SIM card with a soft brush, cloth or q-tip moistened with any type of unflavoured, colourless alcohol.
• Check whether the card is damaged or worn in any way.

If your SIM card is damaged or does not work properly after cleaning, please contact your operator to obtain a new SIM card.
Error message Insert Correct SIM
Your phone is probably SIM-locked to a specific operator's SIM card. This is usually the case when you buy the phone from an operator. SIM- locked phones may be unlocked – contact your operator for more information.

Hi, If you get error message as PIN blocked. Unlock?" You have entered the wrong PIN code too many times. You need to unlock your phone using the PUK (PIN Unlocking Key) code. Your PUK code is provided by your network operator. If you get error message as Insert correct SIM" You have inserted a SIM card that is not supported. Insert correct SIM card, or contact your Service Provider for a SIM unlock code. If you get error message as Phone locked" or "Enter PIN" Your phone is locked and you need to unlock it with your personal PIN. The default PIN is '0000', but you or your network operator may have changed it. I Hope it helped you. Thank you for using ' Fixya ' and have a nice day!!

Check your ipphone by IMEI in www.imei.info my by it was blocked for some reason. Check sim without jailbreak. Try another sim, my be your sim is broken. BEST WAY TO GET TO KNOW YOUR PHONE BETTER

I too have had the "no sim card installed message. What has always worked for me is to go into settings and put the phone into airplane mode for about ten seconds and then switch back to regular mode which causes the phone to reconnect to the ATT network. The sim message goes away. This is also a good fix for when your phone isn't connecting to 3G or showing an "E" instead of 3G.